If we accept the Gaia Hypothesis, then modern reductionist and mechanistic ecology, as taught in our universities, can no longer be defended. However, rather than simply returning to the 'holistic' ecology of Clements and Shelford, a more sophisticated ecology must be developed to take account of the work of such holistic thinkers as C. H. Waddington, Paul Weiss, Ludwig Von Bertalanffy and others.

This paper was presented at the Wadebridge Ecological Centre's Conference: "Gaia: Theory, practice and implications", which took place at Camelford, Cornwall in October 1987. It was published in The Ecologist Vol. 18 No. 2/3, 1988.

Ecology, as an academic discipline, was developed towards the end of the last century. It came into being largely when a few biologists came to realise that the biological organisms and populations which they studied were not arranged at random but were, on the contrary, organised to form 'communities' or 'associations' whose structure and function could not be understood by examining their parts in isolation from each other. Both Frederick Clements and Victor Shelford, two of the most distinguished of the early ecologists in the USA, defined ecology as the "science of communities". [1]

In the 1930s the Oxford ecologist Arthur Tansley coined the term 'ecosystem' [2] which he defined as a community taken together with its abiotic environment, much as Jim Lovelock sees 'Gaia' as the biosphere taken together with its abiotic environment. It is probable that if Clements or Shelford were alive today they would see ecology as the 'science of ecosystems'.

Eugene Odum, one of the most prestigious ecologists alive today (and also one of the few remaining 'holistic' ecologists) defines ecology as "the structure and function of nature". [3] Since he is one of the few modem ecologists to have taken the Gaia thesis seriously, I recently asked him if he would agree to seeing ecology defined as "the structure and function of Gaia" [4] - the overall ecosystem into which nature is organized. He fully agreed that this was a very acceptable definition.

Ecology, seen in this light, would be indistinguishable from Jim Lovelock's 'geophysiology'. It would of necessity be inter-disciplinary. This was clear to the early ecologist who saw ecology as an all embracing super-science. Barrington Moore, for instance, the first President of the American Ecological Society, saw ecology as "the science of synthesis", and as being "superimposed on the other sciences". As he asked his colleagues, in his address to the St. Louis branch of the society in 1919,

"Will we be content to remain zoologists, botanists, and foresters, with little understanding of one another's problems, or will we endeavour to become ecologists in the broad sense of the term? The part we play in science depends upon our reply. Gentlemen, the future is in our hands." [5]

Ideally, of course, ecology taken in that holistic sense of the term, would be non-disciplinary, rather than inter-disciplinary, since the disciplines into which knowledge has been divided have developed in such total isolation that they are difficult to reconcile with each other, still more difficult to merge into an ecological superscience.

What is certain is that ecology, if it is really to explain the structure and function of Gaia, should take into account a whole body of material that was not available to the early ecologists and that has been ignored by modern ones. This would include the Gaia thesis itself; the work of Lynn Margulis on symbiosis, which even the latest ecological literature on cooperation or mutualism in ecology does not mention; and the equally relevant and highly holistic writings of A. N. Whitehead, C. H. Waddington, J. H. Woodger and other members of the Theoretical Biology Club that flourished in the 1940s.

J. H. Woodger, for instance, clearly saw that nature was one. He saw, too, that its functioning could not be understood in terms of a set of separate compartmentalised disciplines, and clearly stated that what was needed was

"a most general science, not immersed in a particular subject matter, but dealing with the relationship between various special sciences and trying to synthesize their most general results." [6]

The similarity between this view and that expressed by Barrington Moore is very striking. Indeed Woodger's Biological Principles, now totally overlooked by ecologists, is an important ecological work which we cannot afford to ignore. The writings of other holistic thinkers such as the Cambridge ethologist W. H. Thorpe, the Swiss psychologist and biologist Jean Piaget and the US cytologist and embryologist Paul Weiss, are also of the greatest ecological value.

Equally relevant is the general systems theory of Ludwig von Bertalanffy of which a variant was developed independently at about the same tune by Ross Ashby. General systems, which must not be confounded with systems ecology, an essentially mechanistic and reductionistic discipline, provides an indispensable tool for the development of a unified science - what one might call "real ecology" - but is equally ignored by modem ecologists. I shall refer to this again later.

The perversion of ecology

However, real ecology is not the order of the day. If modern ecologists take no account of Jim Lovelock's Gaia thesis, of Lynn Margulis' work on symbiosis, or the writings of Whitehead, Woodger, Waddington, Piaget or of Von Bertalanffy's general systems theory, it is because ecology is no longer a "science of communities" nor a "science of ecosystems", let alone a science concerned with "the structure and function of Gaia".

As Donald Worster shows in his most illuminating book Nature's Economy, [7] Odum is today on his own. Worster documents the extraordinary transformation that ecology has undergone in the last 40 years to make it conform more closely to the paradigm of reductionistic and mechanistic science - and thus to conform with the paradigm of modernism, which serves to rationalise, and hence legitimise, our aberrant and necessarily short-lived modem industrial society. Significantly, a closely parallel transformation has taken place in comparative psychology, genetics, evolutionary theory, anthropology and sociology.

Other students of the history of ecological ideas have also noted this transformation. Daniel Simberloff, for instance, tells us:

"Ecology has undergone, about half a century later than genetics and evolution, a transformation so strikingly similar in both outline and detail that one can scarcely doubt its debt to the same materialistic and probabilistic revolution. An initial emphasis on a similarity of isolated communities replaced by concern about their differences: the examination of groups of populations largely superseded by the study of individual populations; belief in deterministic succession shifting with the widespread introduction of statistics into ecology, to realization that temporal community development is probabilistic: and a continuing struggle to focus on material, observable entities rather than ideal constructs". [8]

As a result of this transformation, virtually all the established principles of the old ecology have been abandoned. Thus the whole is no longer seen as being more than the sum of its parts and is therefore studied by examining the parts themselves in isolation from each other: competition has replaced co-operation as the ordering principle in nature: diversity no longer favours stability: ecological succession no longer leads to a stable climax: and the mere mention of the term 'Balance of Nature' elicits from our academic ecologists a condescending smirk, if not a belly laugh.

Ecology has in fact been perverted-perverted in the interests of making it acceptable to the scientific establishment and to the politicians and industrialists who sponsor it. In a way, this is understandable. Were it otherwise, as Worster admits, "ecologists might have disappeared as an independent class of researchers and would not occupy today such an influential position among the sciences."

That said, however, it is by no means clear that ecologists do in fact exert such influence. Indeed, it is unlikely that those ecologists who view the biosphere in purely reductionistic and mechanistic terms can understand the implications of the devastation being wrought by the modern industrial system, and hence that they can understand what action is required to bring this devastation to an end. This partly at least explains the negligible role played in Britain by the British Ecological Society in awakening scientists, politicians and the general public to the present world ecological crisis which threatens the very survival of man on this planet.

The answer to the question, 'What are the implications of the Gaia thesis for ecology?", must thereby depend on which ecology we refer to. Clearly the Gaia thesis cannot in any way be reconciled with the ecology that is taught in our universities today. If the thesis were to be accepted, and today's academic ecologists were to face its implications, then conventional ecology would have to be transformed into a more sophisticated version of the old ecology of Clements, Shelford and Barrington Moore, which today's ecologists have been at pains, over the last fifty years, to discredit.

For that reason, I agree with Lynn Margulis and Dorion Sagan that "the Gaia hypothesis ... is likely to provide the foundations for a new ecology." [9]

The pioneer and the climax world views

The reductionist and mechanistic ecology of today and the holistic ecology that the Gaia thesis will help us create, reflect two diametrically opposed world views. For the purposes of this paper, I shall refer to the former as the 'pioneer world-view' and to the latter as the 'climax world-view'. Let me explain why.

A pioneer ecosystem, that is to say an ecosystem in the earliest stages of development, or one that has been ravaged by some discontinuity, such as a volcanic eruption or an industrial development scheme, displays a whole constellation of closely related features. In a sense, such an ecosystem is the least 'living' of ecosystems or, more precisely, the one in which the basic features of living things are least apparent, for the obvious reason that they have not yet had time to develop.

Such an ecosystem is among other things highly productive, which of course endears it to our modern production-orientated society which can cream off the apparently surplus biomass, process it, and put it up for sale on the international market. The reason why it is so highly productive, of course, is because as soon as it is brought into being, so the healing processes of nature are brought into operation, and the ecosystem changes rapidly via the different stages of ecological succession, until it achieves that state which resembles, as closely as possible, the original climax.

The climax or adult ecosystem, on the other hand, is very unproductive. This must be so both because the climax is the most stable state possible in the local biotic, abiotic and climatic circumstances, and because the achievement of such a stable state appears to be the basic goal of living things. Once achieved, change is kept to a minimum.

The pioneer stage has other essential features that are all closely associated with each other, so much so that to display one of those features means displaying the others too. For instance, there is little diversity and little organisation in such an ecosystem, and, as a result, its constituent parts appear to be arranged in a disorderly or random manner.

This being so pioneering ecosystems appear individualistic and their behaviour seems to be explicable by studying them reductionistically on their own. They are also competitive since they are subject neither to the constraints which might be applied on them by the larger whole, of which they are part, nor to self-imposed internal constraints. Instead, only external constraints (competition, predation, 'management' etc) operate.

Such controls are crude and inefficient; as a result, the life of these ecosystems is punctuated by large and often unpredictable discontinuities which they cannot accommodate without undergoing serious structural changes (population collapses, for instance). In other words they are highly unstable.

Randomness, individualism, competition, crude external controls and instability are indeed the inevitable features of a pioneer ecosystem; they are the features too of a world in which the basic features of living things are still embryonic. They are also the features of the degraded society of which we are part and of the degraded environment in which we live today, both states being the inevitable result of the process of industrial development which we are misguidedly taught to identify with 'progress'. They are, in fact, the features of what Eugene Odum refers to as a "disclimax". [10]

The features of a climax ecosystem, on the other hand, are totally different, indeed diametrically opposed. A climax ecosystem is orderly and its behaviour goal-directed or teleological. Individuals are integrated into larger wholes at different levels of organisation - the family, the small community and the larger society, levels which themselves are part of the hierarchy of the biosphere. For such wholes or systems to exist implies that their parts co-operate with each other.

They also possess highly sophisticated internal control mechanisms which enable them to reduce environmental discontinuities, either by bringing about the appropriate changes to their environment (changes, which among other things, must serve to insulate them from the rigours of their external environment) or, alternatively, by increasing their ability to deal with such discontinuities.

Both such strategies serve to assure the preservation of their basic structure in the face of change and hence, correspondingly, to increase their stability. Such systems are thereby homeostatic, and their fate is no longer dependent on the crude interplay of external forces.

Order, teleology, wholeness, co-operation, stability, and internalised control are the inevitable features of a climax ecosystem, as they are of all complex living things. They are also the features of a climax society - that is, a society culturally designed to flourish as part of a climax ecosystem. The only society that fits this description is a tribal society.

If Jim Lovelock's Gaia thesis has caused a major stir in scientific circles, it is largely because it implies a major shift from the pioneer world-view to the climax world-view. In this paper, I would like to show just how it has affected some of the main features of the former world-view as it is reflected in modern ecology. I would also like to carry the argument a stage further to see how the Gaia thesis itself would be affected by what ecology should be - a 'Gaian ecology', we might call it - one that takes the climax rather than the pioneer state to be the norm.

Holism

Science is still reductionistic or analytical. Underlying it is the metaphysical assumption that the smaller the particles the more concrete and real they must be. W. H. Thorpe defines reductionism as:

"the attribution of reality exclusively to the smallest constituents of the world and the tendency to interpret higher levels of organisation in terms of lower levels." [11]

Atoms are considered particularly real today; however, with the great vogue enjoyed by molecular biology, molecules have also acquired 'realness'. Francis Crick still insists, for instance, that they are the only reality. In saying this, he and other reductionists are committing what Whitehead called "the fallacy of misplaced concreteness", that of abstracting a part and ascribing to it the sort of reality that belongs to the whole. [12]

Science also assumes that for knowledge to be 'exact' and 'mature', it must be formulated in quantitative terms. This can be done where the subject matter is physics, hence the tendency to seek to understand biology, ecology and even sociology in physical terms. However, as Pantin notes, physics has been able "to become exact and mature just because so much of the whole of natural phenomena is excluded from this study". [13]

The physicist, by reason of his training, cannot avoid leaving out "so much of the whole of natural phenomena", but then, as Paul Weiss argues, "there is no reason for us to downgrade nature to meet his inadequacy." [14]

One of the failings of the reductionist world view, is that it sees the world as dead, machine-like, passive and crude. Indeed, as Von Bertalanffy notes, it makes no differentiation "between physical and chemical processes taking place in a living organism and those in a corpse; both follow the same laws of physics and chemistry". [15] He goes on to note: "Concepts like those of organisation, wholeness, directiveness, teleology, control, self-regulation, differentiation and the like, are alien to conventional physics". Yet they are "indispensable for dealing with living organisms or social groups".

The Gaia thesis is holistic - holistic in the extreme. Jim Lovelock notes how "most of us were taught that the composition of our planet could adequately be described by the laws of physics and chemistry". [16] He refers to this as "a good solid Victorian view", but it is wrong. Gaia can only be understood in terms of the structure and function of living things. This is one of the most important messages of the Gaia thesis. Lovelock's argument is still more holistic when he tells us:

"The entire range of living matter on earth, from whales to viruses and from oaks to algae, could be regarded as constituting a single living entity, capable of manipulating the earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts." [17]

This clearly means that the behaviour of Gaia cannot be understood by examining its parts in isolation from each other, which must follow if Gaia is an organisation and therefore more than the sum of its parts. Lovelock even compares Gaia to a biological organism, in that, like an organism, it is a cybernetic system geared to the maintenance of its stability or homeostasis. This thesis would have been acceptable to the early ecologists who regarded an ecological community as very similar to an organism.

Thus A. S. Forbes stated in 1896 that "a group or association of animals is like an organism". [18] C. C. Adams, in the first American book on animal ecology, published in 1913, insisted that:

"the interactions among the members of an association are to be compared to the similar relations existing between the different cells, organs or activities of a single individual." [19]

Thienemann went further. He saw the living things that made up a lake community, for instance, as "a unity so closed in itself that it must be called an organism of the highest order". [20]

Frederick Clements in his book, Plant Succession, published in 1916, tells us that:

"The unit of vegetation, the climax formation is an organic entity. As an organism, the formation arises, grows, matures and dies. Its response to the habitat is shown in processes or functions and in structures which are the record as well as the result of these functions." [21]

In fact, this view of the ecological community as a 'supra-organism' became so well established that Simberloff refers to it as "Ecology's first paradigm". [22]

As Bodenheimer noted at the time, the highly integrated supra-organismic concept of the community was stressed in nearly every textbook of ecology and "backed by established authority". Indeed, it was generally regarded "if not as a fact, then at least as a scientific hypothesis not less firmly founded than the theory of transformation" - that is, of evolution. He went on: "It is, above all, the concept that distinguishes ecology from biology proper". [23]

With the transformation of ecology, which I have already referred to, this view was slowly abandoned in favour of one that better conformed to the reductionist paradigm of science and, hence, with the paradigm of modernism which it serves to rationalise. The resulting reductionistic approach to ecology -which sounds like a contradiction in terms - is normally traced to the writings of H. A. Gleason, whose famous article "The Individualistic Concept of the Plant Association", was first published in 1926 and presented and discussed at the International Botanical Congress that year.

Significantly, Gleason used the usual reductionist argument I have described above. He regarded the association or community as an abstract entity that only existed in the eyes of the beholder, for only the individual was real. The same argument, one might add, is still used by neo-Darwinists today to justify their preoccupation with selection at the level of the individual, and their refusal to see evolution as a process occurring at the level of the 'unreal' ecosystem, let alone of a still more 'unreal' Gaia.

Initially, Gleason's thesis was very badly received. In the words of McIntosh, a noted historian of ecological thought, Gleason was "anathema to ecologists". [24] Gleason himself admitted that for ten years after the publication of his article, he was "an ecological outlaw". [25] His thesis simply did not fit in with the ecological paradigm of the times. However, as the latter was transformed so as to make it conform with the paradigm of science, so Gleason's ideas became increasingly acceptable.

In the 1930s, Arthur Tansley, to whom I have already referred, and who had originally adopted a firm holistic position, abandoned it in favour of a highly reductionist one. He denied the basic holistic principle that the whole is more than the sum of its parts and hence that it is not amenable to study by the reductionist method of science: "These 'wholes' are in analysis nothing but the synthesized actions of the components in associations." [26] A mature science, in his view, "must isolate the basic units of nature" and must "split up the story" into its individual parts.

"It must approach nature as a composite of strictly physical entities organised into a mechanical system. The scientist who knows all the properties of all the parts studied separately can accurately predict their combined results." [27]

If this were so, then the very term 'community' would be superfluous, and he sought to eliminate it from the scientific vocabulary. He denied too that there was anything in common between human associations (which he presumably regarded as legitimate communities) and those to be found among nonhuman plants and animals. The latter were "not linked by psychic bonds" [28] and, hence, for a reason that is not altogether clear, were not true communities.

Today, reductionist ecology is firmly established. Collier and his colleagues go so far as to insist that the individualistic concept "constitutes one of the most influential and widely accepted views at the present time." [29] McIntosh refers to reductionist ecology as "a viable and expanding tenet of current ecological thought" [30], while, Colinvaux, in a well known textbook of ecology, describes the holistic view of the community as a "heresy". [31]

Other modern ecologists go still further and actually claim that their work has provided incontestable proof of the validity of Gleason's philosophy. Curtis, for instance, tells us that "the entire evidence of (his own) plant ecology study in Wisconsin can be taken as conclusive proof of Gleason's individualistic hypothesis of community organisation", [32] while Whittaker regards his "gradient analysis" as providing similar evidence. [33]

This sort of nonsense will become more and more difficult to sustain as Lynn Margulis's work on symbiosis becomes increasingly accepted, and as the new holistic ecology develops. I say 'new' because the holistic ecology of the past had major shortcomings. Among other things, it never explained the relationship between the whole and the parts, let alone that between the parts and the whole. It never in fact really explained how living things were organised.

The organisation of Gaia

One reason is that organisation cannot be explained in reductionist terms, since to admit that there is such a thing, implies that systems are more than the sum of their component parts. Organisation is also difficult to quantify. There have indeed been efforts to do so - by Dancoff and Quastler, for instance - but the type of organisation they are measuring, calculated in terms of Shannon and Weaver's reductionist and mechanistic concept of information, bears no relationship whatsoever to the biospheric organisation with which we are concerned.

To understand this organisation, we must start off by regarding the biosphere as made up of natural systems, operating at different levels of organisation. Natural systems must not be confounded with the systems studied by engineers. They are above all living systems which display all the features of living things already referred to. It is true that many of the definitions of natural systems are vague and could be made to include the engineer's systems, but this was not the intention of Von Bertalanffy, still less of Paul Weiss who defined a system as

"a complex unit in space and in time whose sub-units co-operate to preserve its integrity and its structure and its behaviour and tend to restore them after a non-destructive disturbance." [34]

Weiss's definition is a valuable one since it accentuates the essential aspects of living things such as their complexity, the co-operation between their parts, their tendency towards overall stability, and their ability to restore their basic features in the face of a disturbance - in other words, their capacity for homeostasis.

Lovelock defines Gaia, the all encompassing natural system, in very similar terms as:

"a complex entity involving the earth's biosphere, atmosphere, oceans, and soil; the total constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet." [35]

There is every reason to suppose that such natural systems as molecules, cells, organisms, stable (tribal) communities and ecosystems can be described in similar terms. The behaviour of all such systems, in fact, can be shown, at a certain level of generality, to display the same fundamental features, which would suggest that they are all subject to the same basic constraints and are thereby governed by the same laws. If this is so, then it is clear how General Systems Theory provides a means of unifying science.

Hierarchy

Natural systems, however, are not arranged in a random way. They form a hierarchy. This means that each system is at once part of a larger system and at the same time made up of smaller ones. Paul Weiss notes how this is true of the cell, the main object of his studies. The cell must be seen:

"In a double light: partly as an active worker and partly as a passive subordinate to powers which lie entirely outside of its own competence and control, i.e. supra-cellular powers." [36]

Arthur Koestler tried to show how this principle applied to all natural systems or 'holons' as he called them. He took the double-faced Roman God Janus, one of whose faces looks outwards and the other inwards, as a symbol of the holon, with its two roles within the hierarchy of the biosphere.

Unfortunately, the whole subject of hierarchy is one that has been largely ignored by ecologists and scientists in general. To my knowledge, only two conferences have been held on the subject (one organised by Lancelot Law Whyte and the other by Howard Pattee, and neither was very enlightening; the participants tending to use the term hierarchy very loosely to mean very different things.

Once again Eugene Odum seems to be about the only ecologist today to display an interest in hierarchy. He sees ecology as largely concerned with the upper end of the hierarchy of the biosphere, that is "the system levels beyond that of the organism". [37]

To understand the structure and function of Gaia means studying the hierarchy as a whole, which in turn means understanding the two roles of Janus, its relationship to the larger systems of which it is a part and its relationship to the smaller systems that in turn compose it. The former relationship is taboo among ecologists today, as it is among mainstream scientists in general.

Indeed, if, as most scientists seem to, we were to accept the perfectly preposterous thesis of the selfish gene, then we would also have to accept that living things show no concern whatsoever with the survival of the larger systems of which they are part- no more in fact than do the inhabitants of the modern disintegrated non-society of today. Indeed, those who do show such an interest are described as displaying 'altruism', which apparently only occurs when, on the basis of a 'cost-benefit' analysis, they see co-operation as more likely to favour the proliferation of their genes than the usual much, more 'rational', competition and aggression.

This may indeed be so in a disintegrated or neo-pioneer society and in a pioneer ecosystem; it is not so, however, in a climax society, nor in a climax ecosystem whose members can only behave in that way which satisfies the requirements of the hierarchy of the larger systems of which they are part. As Von Bertalanffy writes:

" ... an enormous preponderance of vital processes and mechanisms have a whole-maintaining character; were this not so, the organism could not exist at all ... " [38]

Ungerer, according to Von Bertalanffy, was so impressed with the "whole-maintaining function" of life processes that he replaced the biological "consideration of purpose" with that of the "consideration of wholeness" [39], a notion that is considerably reinforced by the Gaia thesis.

The main feature of Janus's relationship with its parts must be one of control. Whitman notes how the organism controls the action of the cells, during development:

"Comparative embryology reminds us at every turn that the organism dominates cell formation, using for the same purpose one, several or many cells, massing its material and directing its movements and shaping its organs, as if cells did not exist." [40]

Paul Weiss points out how one cannot understand the behaviour of cells unless they are seen as the parts of a larger system which has the power to "integrate" and "direct" their behaviour. [41] This principle is built into the concept of 'order', which is generally seen as the influence of the whole over the parts, and hence of the latter's degree of differentiation and interdependence and corresponding limitation of choice.

Pattee regards hierarchical control as "the essential and distinguishing characteristic of life". It must be a feature of all hierarchies and hence of all natural systems. [42]

Weiss points to the various mechanisms that multicellular organisms develop to co-ordinate and control the activities of their component cells. He refers to:

" ... the nervous system, the hormone system, the homeostatic maintenance of the composition of the body fluids; for in principle, each one of these subsystems operates within its own scope by the same rule of integrative dominance that the higher system exercises over its components." [43]

Functionally, similar methods of hierarchical control are operative at the level of any ecosystem, though Odum is possibly the only one of today's ecologists to have pointed this out. In a sense, the "wholeness maintaining" behaviour of the parts and the control exerted over the parts by the whole - in other words, the two different roles of Janus - are but different ways of looking at the same phenomenon.

Indeed, one can formulate a law that must apply to all natural systems within the hierarchy of the biosphere, to the effect that behaviour that 'serves' the interests of the whole must at the same time 'serve' the interests of the differentiated parts. If this were not so then there could be no viable whole. I refer to this as the 'Law of hierarchical mutualism'. Let us look at this thesis more closely.

Hierarchical mutualism

That the behaviour of the parts must serve the interests of the whole is clear from another consideration. Jim Lovelock sees Gaia as creating the environment that it requires to maintain its stability. If we accept General Systems Theory, then one must accept that natural systems, at other levels of organisation, are doing likewise. This means that living systems in general depend for their proper functioning and in particular for the maintenance of their stability on the preservation of their specific external environment.

The term 'environment' has never been properly defined. It is used by ecologists in the vaguest possible way to mean little more than "all that is out there". This is also true of Neo-Darwinists, even though they attribute to the environment the capacity for natural selection, a process which is both highly discriminatory and highly teleological.

In reality, 'what is out there', from the point of a natural system within the hierarchy of the biosphere, is nothing more than the larger system of which it is a differentiated part, without which it has no raison d'être and cannot survive. For this reason, the 'whole-maintaining' behaviour on the part of any natural system - that is, the behaviour that satisfies the requirements of the larger system - must also be that which satisfies the requirements of the differentiated subsystem. (I say 'differentiated', as this would not be true of random parts or parts that are not integrated into the hierarchy of the biosphere).

It is in this language, I feel, that one must translate the literature on the subject of morphogenetic fields, a concept introduced in the 1920s (independently, I believe) by Weiss and Gurwitch. Jim Lovelock seems to have little sympathy for this concept. It is nevertheless an essential one, since it accentuates the dependence of natural systems on their respective, and highly specific, internal and external environments all the way up the hierarchy of the biosphere.

Mutualism

If Gaia is a single natural system capable of maintaining its homeostasis, then its parts must co-operate with each other. Lovelock makes this point very clearly. In other words, the most fundamental relationship between the constituents of the biosphere must be one of mutualism. This was also the view of the early academic ecologists. Indeed, at the turn of the century, literally hundreds of papers were published in ecological journals and texts on the subject of mutualism.

Roscoe Pound, an American naturalist, for instance, described, in a celebrated article, all the various forms of mutualism that were known to occur in ecosystems, including pollination and the fixation of nitrogen by bacteria living on the root-nodules of plants. Mutualism in ecosystems was even compared to that occurring in other natural systems such as biological organisms- something which no academic ecologist would dare propose today.

The Chicago school of ecology which flourished in the 1940s also saw mutualism as the principal relationship among living things. One of its leading figures, Warder C. Allee, regarded "an automatic mutual interdependence" as a "fundamental trait of living matter." [44] Then came the great ecological transformation already alluded to, and competition became the order of the day, to be viewed by ecologists and theoretical biologists alike as no less than the fundamental ordering principle in nature-as it still is today.

What is extraordinary is the lack of evidence for this thesis. As Peter Price notes in The New Ecology, "the body of theory is vast"; however, "little has been tested objectively". [45]

Connell is particularly outspoken on the subject. Having reviewed the literature, he was only able to find a single study involving serious experimental work designed to determine if competition played a significant role in the interaction between species.

It is not an exaggeration to say, as does Price, that:

"competition theory lives in a dream world where everything can be explained, but the validity of these explanations has not been adequately established in the real world"

Incredible as it may seem, it is only today that the dogma of competition is being critically examined. To quote Price again:

"Only after fifty years of building an edifice to competition is serious doubt being cast on the evidence for its foundations." [47]

Worse still, the term 'competition' has never even been properly defined. Merrell, in his Ecological Genetics, provides a veritable catalogue of the different ways in which the term is used. There is no point in listing them here, but his summing up is worth quoting:

"Some definitions apply only to animals, others to all organisms - plants as well as animals; some definitions refer only to interspecific competition, others to both intraspecific and interspecific competition; for competition to occur, resources must be in short supply in some definitions but not in others; sometimes the definition is so broad that it does not exclude predator-prey relations, but in others the same trophic level is specified. Given these differences of opinion, it may be hazardous (not to mention presumptuous) to attempt to reach some workable definition of competition." [48]

Nor are the various applications of the 'competitive principle' to ecology any better defined. The 'competitive exclusion principle' for instance, as Merrell also shows, has been formulated by different ecologists in literally dozens of different ways.

In the meantime, so long as competition was the order of the day, co-operation and hence mutualism ceased to be of any interest to ecologists. Vandermere and Boucher, for instance, point out:

"Although some of the most spectacular interspecific interactions in nature are obviously mutualistic, relatively little research, empirical or theoretical, has been aimed at understanding this basic and perhaps prevalent form of interaction." [49]

So too, Risch and Boucher illustrate the extent to which mutualism has been ignored by modern ecologists:

"A survey of 12 ecology texts published within the last five years clearly substantiates the claim that practically the entire discussion of organismic interactions has centred on predation and competition. Of a total of 718 pages devoted to interspecific interactions in these texts, 321 pages concern predator-prey interactions, 362 pages concern interspecific competitive interactions, and only 35 pages discuss any kind of mutualistic relationship. In addition to the disproportionate amount of space devoted to the different interactions, predation and competition are presented as important organising principles, while examples of mutualism (such as. . . cleaning symbioses) are presented as interesting but eccentric exceptions to the general rule." [50]

In the early 1970s, however, there was a sudden resurgence of interest in mutualism. It seemed to manifest itself independently in the work of ecologists at different universities, who were often unaware of each others work. Well known ecologists, who had down-played the importance of mutualism, suddenly changed their minds about it.

Thus Robert May, in 1973, stated that the importance of mutualism "in populations in general is small". [51] However, to quote Boucher, "in only a few years May's appreciation of mutualism changed considerably". He suddenly announced that mutualism was now seen as "a conspicuous and ecologically important factor in most tropical communities". [52] Indeed, in recent years, May has become one of the leaders in encouraging work on mutualism which he sees as "likely to be one of the growth industries of the 1980s". [53]

Today's ecologists, for instance, have started looking at the role played by micro-organisms in the metabolism of complex organisms. Boucher, James and Keller have noted that gut flora are involved in breaking down cellulose and related substances in mutualism with many vertebrates, as well as with termites and other arthropods. Urea is broken down and its nitrogen recycled by rumen bacteria and by the fungal components of some lichens. Toxic secondary plant compounds are also degraded in caeca and rumens by microbial symbionts.

Ecologists have also noted the increasing numbers of parasitic or predatory relationships which, on closer examination, turn out to be mutualistic. Thus McNaughton has pointed out that the normal view of the relationship between grazers and the grass they graze is false:

"Ecologists have tended to view plants as relatively passive participants in short-term interactions at the plant-herbivore interface, suffering tissue reduction from herbivory, and responding in evolutionary time through the evolution of novel anti-herbivore chemicals and structures." [54]

It now seems clear that plants are capable of reacting in a much more dynamic manner to grazing and indeed are capable of "compensatory growth and assimilate reallocation". All in all, McNaughton found nine different ways in which the relationship between grazing animals and the grass on which they graze can be regarded as mutualistic.

Does this then mean, Boucher asks, that mutualism is "destined to be part of a new synthesis, in which Newtonian ecology is replaced by a more organicist, integrated, value-laden view of the natural world?" He is not too optimistic on this score. The reason is that "our present theories of mutualism are still basically mechanistic, mathematical, fitness-maximising and individualistic." [55]

Unfortunately this is only too true. D. H. Janzen considers that "Mutualisms are the most omnipresent of any organism-to-organism interaction." [56] However he insists that "natural systems larger than the individual cannot be mutualistic." [57] The reason is that:

"A mutualism is an interaction between individual organisms in which the realized or potential genetic fitness of each participant is raised by the actions of the other. The participants are called mutualists. Since a species has no trait that is analogous to the genetic fitness of an individual, mutualism cannot be defined with reference to species." [58]

If a species cannot be involved in a mutualistic relationship nor can inanimate forces, nor even seeds:

"By definition, inanimate dispersal of seeds is not a mutualism. Wind and water have no fitness. Explosive capsules are plants that move themselves. Burrs stuck on horses legs do not benefit the horse. Hard red Erythrina seeds swallowed by a fruit pigeon and defecated entire do not benefit the pigeon. The Squirrel does not benefit from the acorn that it buries and never recovers. An ant-acacia whose fruits are eaten by a bird that carefully spits out each seed below the parent ant-acacia does not benefit." [59]

Boucher considers it inevitable that ecologist should see mutualism in this narrow reductionistic way:

"While arguing that nature is an integrated whole and that everything is connected to everything else, we continued researching with theories that said that communities are no more than sets of individual organisms. The problem, in other words, is one of cognitive dissonance - the difficulty of working with two sets of ecological ideas, based on different fundamental assumptions and ultimately in conflict." [60]

What is, in fact, required is a paradigm shift. Mutualism must be seen in the light of a climax, rather than a pioneer, world-view. The Gaia thesis can do a great deal to help bring about such a transformation.

Stability

One of the basic features of the biosphere is its extraordinary stability. This is implied by Stephen J. Gould and other proponents of the theory of punctuated equilibrium who point to the fact that many forms of life have not change for hundreds of millions of years. This point is also made by Jim Lovelock, who notes the great stability of Gaia over the last few thousand million years. Though Darwin may have been the prophet of evolution, and hence of change, he was also impressed by the stability of the living world. Thus, he tacitly admitted in a letter to Lyell that he was not wholly happy with the term 'natural selection': "If I had to commence de novo, I would have used 'natural preservation.' " [61]

Preservation must be important, since without it there can be no structure which displays any sort of permanence. If an organism or community or species or ecosystem has an identity at all, it is because of its persistence. Indeed, a development process whose end-product is not preserved, at least for a period of time, seems to be self-defeating.

Indeed, within the biosphere, change seems to occur not so much because it is desirable per se - indeed it would seem that nature tries desperately to avoid it - but because, in certain conditions, it is necessary as a means of reducing the need for other, more destructive, changes.

If this is so, then we should accept that stability is the overall goal of life. This was the view of Claude Bernard who wrote:

"All the vital mechanisms, varied as they are, have-only one object, that of preserving constant the conditions of life in the internal environment." [63]

Though the concept of stability is of concern to modern ecologists, its treatment is rather muddled. Hollings, whose writings are occasionally referred to by Jim Lovelock, regards a stable ecosystem as one that returns to an equilibrium state after a temporary disturbance and, what is more, "with the least fluctuations". [64]

He includes in this category living things that have not undergone change for a very long time. These, he does not regard as persistent. He then contrasts stable ecosystems with resilient systems which are characterised by large fluctuations. Those alone, he sees as persistent.

Hollings' work has been taken up by Eric Jantsch and Ilya Prigogine, whose theoretical writings, as I have tried to show in my article "Superscience, its Mythology and Legitimisation", [65] serve, above all, to provide the mythology required for rationalising high-technology, and in particular genetic engineering.

It involves singing the praises of individualism, competition, aggression, and instability, and hence of such discontinuities or fluctuations as the wars, epidemics, famines, and climate changes which must necessarily characterise our atomised, high-technology, neo-pioneer society. At the same time, cooperation and stability are deprecated - necessarily so, since in such a society they are conspicuous by their absence.

However, Hollings' position does not stand up to serious scrutiny. To begin with, no living system returns to an equilibrium state after a disturbance, but rather it moves to a new position that is as close as possible to the original one. The reason is that unlike the behaviour of machines, the behaviour of living things is irreversible. Each experience must affect a living thing in some way, and such effects cannot be eradicated.

The fact is that living things change, though some do so more than others, and indeed must do so in the interests of preventing bigger and more destructive changes. For this reason, a stable system is not an immobile one - such a system could not possibly be stable in the face of a changing environment - but one that is capable of maintaining its basic structure and function in the face of change.

In other words, nothing in the real world corresponds to Hollings' stable ecosystem. What is more, the closest approximation to such an ecosystem - say a tropical rain forest - cannot, by the wildest stretch of the imagination be regarded as 'non-persisting'. On the contrary, ecosystems that have lasted without major modifications for more than 100 million years are obviously highly persistent.

They may indeed be facing annihilation today, but then they could hardly have predicted the occurrence, let alone the scale, of modern logging activities. Natural systems are neither omniscient nor omnipotent - and cannot be expected to deal adaptively with phenomena that have never occurred during their 100 million years of experience.

It is certainly true that a climax ecosystem has committed itself to an environment of a specific type, which means that it can only survive if the main features of that environment are maintained. This must make the system vulnerable to very radical changes that might affect the main features of its internal or external environments. But then, it is justified in 'expecting' (if I can use such anthropomorphic terms) that they will be so maintained.

This must follow from the fact that climax systems - such as Gaia, as Jim Lovelock has noted - exist in an environment whose main features they have themselves created, and which are precisely those that minimize the incidence and seriousness of potentially disruptive changes, and which otherwise maintain those conditions required to safeguard their stability.

Thus rainforests can 'expect' the occurrence of the rainfall they have come to require for the simple reason that they themselves have generated much of it via evapotranspiration; so much so that they are in this respect practically closed systems; the Amazonian rainforests, for instance, appear capable of generating up to 75 per cent of the rainfall they receive.

Rainforests can also confidently predict that the nutrients required for their sustenance will be available, for they themselves have generated these nutrients. Indeed, tropical forests, as everyone knows, grow on very poor soils, but the litter they generate is recycled so quickly, and the trees have developed such effective means of extracting the nutrients from it, that no shortage of nutrients is ever likely to occur.

Many ecosystems that are characterised by large fluctuations or discontinuities, such as grasslands, are pioneer ecosystems which will, if undisturbed by man, eventually develop into climax ecosystems. Others, such as the Californian chaparral, appear themselves to be climaxes existing in biotic, abiotic and climatic conditions which do not favour further development. What seems clear, however, is that all such systems are striving to achieve what, in the conditions in which they exist, is the maximum achievable stability. Their goal remains the preservation of their basic structure and function in the face of change, and they succeed in achieving it to the best of their capacities. One must thereby agree with Waddington that Hollings' distinction between 'stability' and 'resilience' is based on "a confusion between two different types of stability." [66]

This fits in better with Eugene Odum's own distinction between 'resistance stability' (which he defines as "the ability of au ecosystem to resist perturbations and maintain its structure and function intact") [67] and 'resilience stability' (which he defines as a system's ability to recover when it is disrupted by a perturbation). [68]

As an example of the former, he takes a forest of Californian Redwoods, whose thick bark enables them to withstand fire, but which take hundreds of years to recover if destroyed. 'Resilience stability', on the other hand, Odum exemplifies by the Californian Chaparral vegetation which burns easily but which recovers quickly.

Significantly, Odum does not suggest that the Redwood forest is not persistent or that the chaparral is not stable. Both assure their survival in the face of the range of changes which, in terms of their experience, they are justified to 'expect', though the former can do so at considerable less cost to its basic structure and function than the latter.

Unfortunately, little work seems to have been done by ecologists to test the thesis that ecosystems can maintain their own stability or homeostasis: however, what work has been done tends to confirm the thesis. The best known experiments in this field are those conducted by Simberloff and Wilson in 1969. These researchers removed all the fauna from several small mangrove islets and then closely watched the way they were re-colonised by terrestrial arthropods. Though, in the end, the islets were populated by very different species from the original ones, the total number of species was very much the same as originally.

The same data were re-examined three years later by Heatwole and Levins. Their interest was to classify the different species in terms of trophic organisation, noting the number of species in each of the trophic categories (herbivores, scavengers, detritus feeders, predators, etc). The results were highly significant. They showed that the trophic structure of the communities on the different islets displayed a remarkable stability even though the species composing each of the trophic levels had undergone a considerable change. This experiment clearly illustrates the principle of systemic homeostasis and stability, for the system had undergone change, but its basic structure had been preserved.

Significantly, mainstream ecologists have refused to accept this interpretation. For example, Putman and Wratten, the authors of a recent textbook on ecology, insist that the data do not point to the "recovery of a disturbed system" but rather to the "establishment of a new community after total de-faunation". [69]

Simberloff insists the same result could, in any case, have been achieved stochastically - in other words, that it is consistent with the postulate of randomness, a tenet which is critical to the paradigm of modernism. Horn tries to explain the ecological healing process, or successional development towards a stable climax, in terms of the statistical properties of Markov chains, which suggests that, rather than being a device for achieving or restoring homeostasis, it is but a statistical phenomenon.

We are faced here with but another rather pathetic attempt to preserve the credibility of the paradigm of reductionist ecology or "the pioneer world-view" in the face of yet further evidence of its inadequacy. This demonstrates once more the need for a new Gaia-inspired holistic ecology.